Single fiber optical tweezer for particles multi-dimensional arrangement

We propose and demonstrate a single fiber optical tweezer for particle multi-dimensional arrangement based on a high-order Bessel-like beam produced by concatenating a few-mode fiber and a step-index multimode fiber. We use the mode division multiplexing technology to produce the high-order Bessel-like beam with uneven energy distribution. The LP11 and LP21 mode beams are excited by docking a 980 nm single-mode fiber at the outlet of the light source to a few-mode fiber with a defined offset. The few-mode fiber allows LP01, LP11, and LP21 mode beams to be spread in. The high-order Bessel-like beam is focused by a high refractive index glass microsphere integrated on the fiber end facet. The LP01 mode beam is used to trap particles and array them in a one-dimension space (linear arrangement), the LP01 and LP11 mode beams are used to trap and array particles in a two-dimension space (planar arrangement), and the LP01, LP11, and LP21 mode beams are used to trap and array particles in a three-dimension space (solid arrangement). The proposed fiber optical tweezer is simple in structure and will allow us to examine the interaction between the cells when held in close proximity.